rx_demodulate.m

ofdm系统仿真

%Demodulate
function [rx_bits]  = rx_demodulate(rx_symbols, sys_parm)

    global ofdm_data_parm_const;
    global ofdm_data_parm_var;
    
    rx_bits = [];
    ofdm_data_parm_var.Index = 0;
    
    for n = 1 : sys_parm.NumOFDMSymbols
        
        update_ofdm_data_parm_var;
        
        %Demodulation
        demod_in = rx_symbols(n, ofdm_data_parm_var.DataSubcIdx);
        
        switch ofdm_data_parm_const.Modulation
            case 0 %BSK
                demod_out = pskdemod(demod_in, 2);
            case 1 %4PSK
                demod_out = pskdemod(demod_in, 4);      
            case 2 %16QAM
                demod_out = qamdemod(demod_in * sqrt(10), 16);          
            case 3 %64QAM
                demod_out = qamdemod(demod_in * sqrt(42), 64);     
        end
        
        demod_bits = (de2bi(demod_out, 'left-msb'))';
        demod_bits = reshape(demod_bits, 1, prod(size(demod_bits)));
        rx_bits = [rx_bits, demod_bits];
    end
end